Electric range switch



F. P. GATES 2,454,646

ELECTRIC RANGE SWITCH 3 Sheets-Sheet 1 Filed April 29, 1944 MMM Nov. 23,1948. F. P. GATES ELECTRIC RANGE SWITCH 3 Sheets-Sheet 2 Filed April 29,1944 .Tfivenivr FREDERIC P. GATES qyhzsal-iarrzeya Nov. 23, 1948. F. P.GATES ELECTRIC RANGE SWITCH 3 Sheets-Sheet 3 Filed April 29, 1944 III/0!WWW? "mm R N lll.

Jr'zveniar FREDERIC I? GATES {yhz'a mrne y Patented Nov. 23, 1948ELECTRIC RANGE swrron Frederic P. Gates, Toronto, Ontario, Canada, as-

slgnor to The Arrow-Hart & Hegeman Electric 00., Hartford, Conn., acorporation of Connecticut Application April 29, 1944, Serial No.533,355

15 Claims. 1

This invention relates to rotary switches for electric ranges,particularly of the type wherein erted against resilient contacts whichmove parallel to the axis of rotation of the rotary element.

It is an object of my invention to provide a rotary switch of theforegoing type with certain improvements in structure of the rotary cammember and arrangement of contacts with relation thereto for enablingreduction in the size of the switch.

Another object of my invention is to provide improved form of rotaryelectric switch mechanism of the foregoing type, providing a switchspindle and cam member molded as a unit from insulating material.

Another object is to utilize the fixed contacts in a switch of theforegoing type to hold parts of the switch in place during assembly.

Another object is to provide for inspection. of the interior contactparts after they are assembled, by the provision of removable casingwalls.

Other objects and advantages of my invention will appear as it isdescribed in connection with the accompanying drawings.

In the drawings Fig. 1 is a vertical section view of a switch embodyingthe invention;

Fig. 2 is a plan view of the casing and contacts, the cam and coverbeing removed:

Fig. 3 is a diagrammatic view of the bottom surface of the cam memberused in Fig. 1;

Fig. 4 is a plan view of the switch casing;

Fig. 5 is a side view of the switch casing;

Fig. 6 is an end view of the switch casing, partly broken away;

Fig. '7 is a vertical section view of a second form of the invention;and

Fig. 8 is a plan view with the cover removed of the second form ofinvention.

Referring to the drawings, the invention comprises a base III ofrectangular plan, hollowed out, in its central portion for the receptionof operating parts. Fixed contacts l4, l5, l6 and I1, stamped from sheetmetal into rectangular or other suitable shape, are preferably mountedin spaced rectangular recesses l8, I9, 20, 2|, formed in the interior ofone end wall of the switch base. with insulating barriers, such as 22,23, molded integally with the base extending between adjacent contacts.The bottoms of inner recesses l9 and 20 are lower than the bottoms of [8and 2|.

whereby the fixed contacts are mounted on different levels and extendtoward the middle of the switch. The fixed contacts may be secured inposition by metal rivets 24 passing through apertures suitably providedin one end of each contact and aligned with passages formed in theinsulating base. These rivets nia also serve to secure wire terminals,such as 25,' on the bottom surface of the insulating base inconventional fashion.

Movable contacts 34, 35, 36, 31 are preferably stamped in the form ofstrips from thin spring sheet metal and extend in parallel relation fromthe opposite end of the switch casing a distance, sufficient to underliethe ends of the fixed contacts l4, I5, l6, l1 respectively. The movablecontacts are preferably secured at one end by rivets, in a similarmanner to the fixed contacts. Outer contacts 34 and 31 are mounted onledges 40 and 4|, while inner contacts 35, 36 are mounted in recesses38, 39, formed in the insulating base below the ledges 40, 4|. Themovable contacts each have cam projections, like 360, pressed upwardlyout from their central portions at one side-edge.

For moving the movable contacts, there is provided amolded rotaryinsulating member 50 having a split spindle portion 5|, with its partsslightly resilient and divergent for insertion within a switch handle tofrictionally hold it. The spindle portion extends through a metalliccover 54 seoured over the upper face of the base by rivets, bolts, or inany other suitable fashion. The central portion of the rotary insulatingmember is provided with circular enlargements of different radii, eachenlargement having on its under surface inner and outer concentric camsurfaces or tracks, such as 55, 5B, 51, 58 at different radial distancesfrom the axis of the spindle so as to co-act with cam portions 340 to 31of the several movable contacts as the rotary member is turned tooperate the switch. The cam surfaces in any track may be of hill andvalley form, as may be observed in Fig. 1. There, the lower outer trackhas elevations a, b and 0, whereby the contact 35 (see Fig. 2) canoccupy an intermediate substantially level condition when cam 35c restson level b, or can be moved to downward by hill a, or permitted tospring upward by valley 0. In each of the up and down positions, thecontact may engage a fixed contact, i. e., on the under side of 15, orwith a contact (not visible) in the floor of the casing beneath themoving end of 35. The movable contacts are all slightly biased upwardlyto normally tend to engage the fixed contacts overlying them. A bossportion 52 extends from the bottom end of the cam member into thecylindrical bore in a boss 53 in the bottom of the casing Hi.

Thus, as the rotary member 50 turns the movable contacts will engagetheir fixed contacts by inherent spring action when the cam portionsenter a cam recess; and the movable contacts will be forced out ofengagement with their fixed contacts when the cam portions ride upon thesurface or on a hill on the rotary member.

To position the rotary member in several positions as it rotates,indexing means in the form of a pair of spring-pressed balls 8t workingin pockets 6| within the rotary member 50 around the spindle portion iare provided, and the balls engage in a series of circularly-arrangedspherical indentations 62 in the cover as the cam member turns into oneposition after another.

Because the inner set of movable contacts 35, 36 is operated by camsurfaces on a level below the cam surfaces that operate the outer set ofcontacts 34, 3?, it is possible to move the fixed contacts i5, IS innearer to the axis of the spindle. This enables the switch casing to bemade shorter than would otherwise be possible with contacts andoperating parts of the same size, which is an important consideration inrange switches where conditions of limited space are imposed.

In molding the spindle portion 5!] of the rotary member, small opposedribs Eiir are provided within the split or slot his, so that themovement of the two halves of the spindle is limited to preventbreaking.

In Figs. 7 and 8 (in which like reference numerals refer to like partsof previous figures), a modified form of the invention is illustrated.In that form, the cam surfaces all face in the opposite axial direction,i. e., they are on the top of the central enlargements or cam portionsof the rotary member 115d. I'he movable contacts I34, H35, H35, tilloverlie the camsurfaces of the member I58 and have their own camportions (such as i340) downwardly pressed.

The stationary contacts H 1, H5, H6, ill, on two difierent levels asbefore, underlie the contacting ends of the movable contacts and areengaged thereby when the cam. portions (such as i360) seat in camrecesses in the rotary member 558. At other times, the movable contactsare forced out of engagement with the statlonary contacts. As in thefirst-described modification, the middle stationary contacts can extendover the lower cam surfaces, enabling the switch casing to be madeshorter than heretofore. Also, in assembling the switch after the fixedcontacts are fastened to the base, the two overlapping contacts M5, M6hold the rotary member ltd in position so that it does not. fall outbefore the cover or bridge plate is assembled.

The indexing means in Figs. 7 and 8 comprises spring-pressed balls tilocated in pockets or cavities H62 in the bottom of the base and arepressed into one or another of a series of circularlyarrangedindentations M53 in the bottom of the cam portion of the rotary member858.

In both forms described, the molding of the rotary member as a unit withits operating spindle saves expensive metal and assembly costs andreduces the number of switch parts.

In switches of the type disclosed, it is particularly necessary to beable to inspect the action, alignment and engagement of the contactsbefore the switch is passed on for use and sale. To enable this to bedone, even though the contacts may be located beneath the cam portionsof the rotary member, removable side walls 80 may be provided, which maybe snapped into place after the inspection. Referring to Figs. 5, 6 and7, the casing or base in there shown has its side walls open with asemi-circular upward extension 82 from the bottom edge of the opening 83to provide additional rigidity to the casing. In the bottom edges of theopening are grooves 84 to receive the feet 86 of a thin wall plate ofsheet insulation 80 whose outline is substantially the same as that ofthe opening 83. To hold the top edge of the wall plate 80, the sideedges of a metal switch cover plate 85 may be bent over to provideflanges 88 divided at their center by tongue 98 bent parallel to theflanges but spaced therefrom a distance slightly greater than, butapproximating the thickness of the wall plate 80. Because of slightresiliency of the wall plate, it is possible, after inserting feet 86 ingrooves 84, to snap the upper edge between the flange 88 and the tongue90, or vice versa.

Alternatively, grooves may be formed in the short side edges of theopening 83 and the plate 80 flexed to enable insertion of the shortedges of the plate therein. In such case, the flanges 88 and tongues 90and grooves 85 may be omitted, and the top and bottom edges of the plate86 will abut the under side of the cover and the bottom edge of theopening 83, respectively.

The cover plate may be held in place by bolts or secured by arms 92: ofthe shape shown in Fig. 6, extending from the ends of the cover and bentdown into channels in the casing walls.

It will be understood that in the interest of simplicity ofillustration, the casing details of Figs. 4-6 have been omitted from theremaining figures, but are or may be incorporated in the switch as madeand used, for the reasons given. It is particularly important that thecasing of Figs. 4-6 be used when the cam of Figs. 1, 2 and 3 is used,for in that form it is impossible otherwise to inspect the contactsafter assembly.

The subject matter of the casing structure just described is claimed ina divisional application, S. N. 18,428, filed April 1, 1948, entitledElectric switch casing.

Many modifications within the scope of my invention will occur to thoseskilled in the art. Therefore, I do not limit it to the specificembodiments disclosed.

I claim:

1. A rotary electric switch, comprising fixed and movable contacts, arotary member for moving said movable contacts in directions parallel tothe axis of rotation of said member, said rotary member having aplurality of cam tracks concen trically arranged at difierent distancesfrom the axis of rotation, and all facing in one axial direction,certain of said tracks being located on one surface of said member andother of said tracks being located on another surface spaced axiallyfrom said first surface.

2. A rotary switch comprising fixed and movable contacts, a rotary cammember having a pinrality of cam tracks on each of two different levelsfacing in the same axial direction and concentrically arranged atdifferent distances from the axis of rotation, each of said tracks beingcooperatively associated with a contact which is movable by its tracksseparately from the other movable contacts, and said tracks causingengagement and disengagement of said fixed contacts by said movablecontacts by movement in different parallel planes.

3. A rotary switch comprisingfixed and movable contacts, a rotary cammember molded from insulating material as an integral unit with aspindle, said member having enlarged central portions with a pluralityof cam tracks on each of two diil'erent levels facing in the same axialdirection and concentrically arranged at different distances from theaxis of rotation, each of said tracks being cooperatively associatedwith a contact which is movable by its tracls separately from the othermovable contacts, and said tracks causing engagement and disengagementof said fixed contacts by said movable contacts by movement in differentparallel planes.

4. A rotary switch comprising fixed and movable contacts, a rotary cammember having a plurality of cam tracks on each of two different levelsfacing in the same axial direction and concentrically arranged atdifferent distances from the axis of rotation, each of said tracks beingcooperatively associated with a contact which is movable by its tracksseparately from the other movable contacts, and said tracks causingengagement and disengagement of said fixed contacts by said movablecontacts by movement in different parallel planes, certain of said fixedcontacts and certain of said cam tracks being positioned in overlappingnon-engaging relation.

5. A rotary switch comprising fixed and movable contacts, a rotary cammember having a plurality of cam tracks on each of two different levelsfacing in the same axial direction and concentrically arranged atdifferent distances from the axis of rotation, each of said tracks beingcooperatively associated with a contact which is movable by its tracksseparately from the other movable contacts, and said trackscausingengagement and disengagement of said fixed contacts by said movablecontacts by movement in different parallel planes, certain of said camtracks on one level and certain of said fixed contacts which cooperatewith movable contacts controlled by cam tracks on another level beingarranged in overlapping non-engaging relation.

6. A rotary switch comprising fixed and movable contacts, a rotary cammember molded from insulating material as an integral unit with aspindle, said member having enlarged central portions with a pluralityof cam tracks on each of two different levels facing in the same axialdirection and concentrically arranged at different distances from theaxis of rotation, each of said tracks being cooperatively associatedwith a contact which is movable by its tracks separately from the othermovable contacts, and said tracks causing engagement and disengagementof said fixed contacts by said movable contacts by movement in differentparallel planes, certain of said fixed contacts and certain of said camtracks being positioned in overlapping nonengagin relation.

7. An insulating base, a rotary cam member mounted forrotation thereinand having a plurality of concentric cam tracks some on one level andsome on another level spaced axially from the first level and all facingin one axial direction, flexible contact members extending across saidbase and individually operated by said cam tracks, fixed contact membersengaged and disengaged by said fiexible contacts, certain of said fixedcontacts and one of said cam tracks being arranged in overlappingnon-engaging relation.

8. An insulating base, a rotary member mounted therein molded frominsulating material with integral spindle and cam portions, said camportions having a plurality of concentric cam tracks located ondifferent levels and facing in the same axial direction, flexiblecontacts extending over said tracks and individually operated thereby,fixed contacts engageable and disengageable by said flexible contacts,and certain of said fixed contacts and tracks being arranged inoverlapping non-engaging relation.

9. An electric switch part comprising a molded insulating one-piecemember having cam portions, a spindle portion for reception of anoperating handle and a bearing boss portion.

10. An electric switch part comprising a molded insulating one-piecemember having cam portions, a spindle portion for reception of anoperating handle and a bearing boss portion, said cam portions being ofdifferent diameters and having concentric cam tracks formed on faces ofsaid cam portions facing in one axial direction.

11. An electric switch part comprising a molded insulating one-piecemember having cam portions, a spindle portion slotted diametricallyproviding resilient arms receivable within and for friction'ally holdingan operating handle, and a bearing boss portion on the end of saidmember opposite said arms.

12. A rotary electric switch comprising a hollowed insulating base, amember overlying the base and secured thereto and having a pinrality ofindentations arranged around an opening, a rotary cam member within saidcasing, a spindle for rotating said cam extending through said opening,a plurality of pockets in said cam, indexing balls and springs in saidpockets and pressed into said indentations selectively, cam tracks on adownwardly facing surface of said cam member, and movable contactmembers operated by said cam tracks for engagement with anddisengagement from stationary contacts.

13. A rotary electric switch comprising a hollowed insulating base, amember overlying the base and secured thereto and having a plurality ofindentations arranged around an opening, a rotary cam member within saidcasing, a spindle for rotating said cam extending through said opening,a pluralty of pockets in said cam, indexing balls and springs in saidpockets and pressed into said indentations selectively, and movablecontact members operated by said cam for engagementwith anddisengagement from stationary contacts.

14. A rotary electric switch comprising a hollowed insulating base, amember overlying the base and secured thereto and having a plurality ofindentations arranged around an opening. a one-piece molded insulationmember hav ing cam portions and having a spindle portion extendingthrough said'opening, spring-pressed indexing means located in aplurality of pockets in said cam portion and pressed into saidindentations selectively, a plurality of concentric cam tracks on adownwardly facing surface of said cam member, and movable contactmembers operated by said cam tracks for engagement with anddisengagement from stationary contacts.

15. A rotary electric switch comprising a hollowed insulating base, amember overlying the base and secured thereto and having a plurality ofindentations arranged around an opening, a one-piece moldedinsulation'member having cam portions and having a spindle portionextending through said opening, spring-pressed ,464,66 1 7 8 indexingmeans located in a, plurality of pockets REFERENCES CITED in said camportion and press'ecl into said. illdentations selectively, a pluralityof concentric Th following references are of record in the cam tracks ona plurality of downwardly facing file Of this patent:

axially-spaced surfaces of said cam member, 5

movable contact members extending across said UNITED STATES PATENTS basebeneath said surfaces and operated by said Number Name Date cam tracks,stationary contacts engageabie by 2,203,224 Kimball June 4, 1940 saidmovable contacts, certain of said stationary 3 Basseti? Sept. 2, 19412,255,0il2 Rodanet Bent 2, 1941 contacts and cermln of sold tracks beingin over= m 2,3013% Kemplon Z-.. Nov. 19,, 1942 lapping relation. I

FREDERIQ p, G g 2,368,679 Pfilpp Fe in, 1

